Cushioning bumper for loading docks



Jan. l2, 1965 R. H. PFLEGER 3,165,305

cusHIoNING BUMPER FOR LOADING Docxs Filed March 20, 1965 UnitedStatesPatent() This invention relates to truck dock bumpers of the typeadapted to be mounted on the front face of a loading dock to protectboth the dock anda truck backing up into position to be loaded orunloaded. This invention is thus Vclassifiable'with that of the SchuylerPatent `No.-

Bumpers of this type generally consist of a stack of fiat rubber orrubber-like units rectangular in shape and usually cut from discardedautomobile tire casings. This stack of vresilient pieces or units isclamped between a pair of stiff end plates which are held together byone or more tie rods. The end plates usually have some attaching meansfixed thereto by which the entire bumper may be mounted on the frontface of a dock in position to be engaged by the rearend of a truck beingbacked into loading or unloading position in front of a dock.

All bumpers of'this type heretofore available have had one seriousdefect. After the bumpers were in service for a while, they would sag inthe middle. Not only did this result in a very unsightly appearance--italso detracted from the usefulness of the bumper. The present inventioneliminates this defect.

This invention also has as its purpose to provide an improved manner ofmounting dock bumpers, whereby a plurality of bumpers can be mounted inclose end-to-end relation with all of the bumpers in exact alignment andvbearing solidly against the face of the dock so as to afforddock-length protection without unsightly unprotected gaps. f

With the above and other objects in view which will i appear as thedescription proceeds, this invention resides derstood that such changesin the precise embodiment of the hereindisclosed invention may be madeas come Within the scope of the claim.

The accompanying drawing illustrates one complete example ofthe physicalembodiment of the invention, constructed according Ito the best mode sofar devised for the practical application of the principles thereof, andin which:

FIGURE 1 is a perspective view of a truck dock bumper embodying thisinvention, said View having a portion thereof broken away and invsection to better illustrate structural details;

FIGURE 2 is a fragmentary longitudinal sectional view through one endportion of the bumper illustrating the same mounted; and

FIGURE 3 is a front view of a plurality of bumpers (with the medialportion of the middle bumper broken away) to illustrate the closeend-to-end disposition made possible by the mounting means of thisinvention.

A Referring now particularlyto the accompanying draw- Y* ing, thenumeral 4 indicates generally a stack of resilient units, each of whichis a flat plate-like member 5 rectangular in shape, so that the stackhas wide front and rear faces 6 and 7, respectively and narrow top andbottom faces 8 and 9, respectively. This stack of resilient units isclamped between` a pair of stiff metal'end plates 10 by means of a bar11 which has its ends solidly secured to the plates 10 and passesthrough aligned holes 12 in the resilient units. n

j erably by welding.

Mice

Preferably the resilient units 5 are made of tough rubber and fabricsections cut from the tread portion of discarded truck tires. The stackis held under great pressure at the time the ends of the tie bar 11 aresecured to-the end plates 10, the securement being effected pref-Attention is directed to thefact that the` end plates 10 have their rearedges flush with the rearface of the stack and their top and bottomedges flush with the top and bottom faces of the stack, but the frontedge of the end j plates is spaced rearwardly of the front face of thestack.

Accordingly, when the bumper is. mounted in position, the end plateswill not be damaged byV a truckl backing against the bumper, nor willthe end plates interfere with the cushioning function of the bumper.

Each end plate 10 has a pair of substantially identical mounting angles13 welded thereto. These angles are preferably short lengths of angleiron. At one end of the bumper, one of the mounting angles is flush withthe top face of the bumper and the other is spaced from that top angleand from the bottom face of the bumper a distance slightly greater thanthe width of ythe mounting angles, while at the opposite end of thebumper the situation is reversed, so that one ofthe mounting angles isflush with the bottom face of the stack.

This offset relationship in the location of the mounting angles at Itheopposite ends of the bumper enables the mounting angles of endwiseadjacent bumpers to be interengaged or interlaced, as shown in FIGURE 3,to permit close end-to-eud disposition of the bumpers in exact alignmentand flat against the front face 14 of a dock 15. Studs 16 anchored inthe dock 15 and passing through holes in the attaching flanges of themounting angles with clamp ing nuts 17 threaded on the studs, secure thebumpers to the dock.

t Obviously, of course, where the bumpers are not intended to be mountedin a row, the mounting angles need not be arranged in the offset orstaggered manner described and shown, but could be symmetricallylocated.

An important feature of this invention resides in the rectangular crosssection of the tie bar 11 and its specific orientation disposing itsWide fiat sides in parallelism with the front and rear faces vrof thestack of resilient units. Thus, by having the tie bar tit snugly in theholes 12 in the resilient units, great strength against sagging of thebumper in .its middle is achieved. Because the stack of resilient unitshas this rectangular tie bar extending therethrough from end-to-end,andV because of the described orientation of the bar with respect to thecross sectional shape of the stack, and as seen in the drawing,

. especially FIGURE 3, the width of the bar is on the order of one-thirdthe length of the long sides of the rectangular units, the bumper Willnot sag in the middle -as was so often the case in bumpers of this typeheretofore available, especially after they had been in use for sometime. Consequently, the bumper of this invention not only retains itsappearance. of strength and vigor throughout many years of useful life,but has all portions thereof most strategically located when mounted ona dock.

From the foregoing description, taken in connection with theaccompanying drawing, it will be apparent to those skilled in thisk artthat this :invention provides a substantial improvement in dock bumpersused to protect docks and trucks, and that by Virtue of its novelfeatures, the bumper of this invention not only retains its 'appearanceof strength and vitality, but can be mounted in close end-to-endrelationship with other similar bumpers, with all of the bumpers fiatagainst the front face of the dock to which they are secured, and all ofthem in exact align unsightly unprotected gaps.

What is claimed as my invention is:

A bumper for truck loading docks comprisingz' A. a stack of fiat uniformthickness rectangular units of Y resilient material, Said stack havingwide front and rearl faces'and `narrovv'top. and bottom. faces and theindividual units having aligned. rectangular cen- `rtrally locatedholes, With long sidesthat areparallel to the long Vsides'of 'therectangularV units andklienceV f parallel tothe Wide front and rearfaces of theistack l 10 B. a stiff metal end platedatwise overlying theouter Vand muchjnarrower top and bottom ends;

face of eachendmost unit of the stack; Y

aligned holes in said resilient unit and having its ends secured -to themetal end plates to. tie the latter *together with the: stack `ofunitsvtightly clampedY therebetween, said bar having a'uniforrnrectangularl crossfsection` forits' entire length of '-a' size and-shape to snugly fit -the aligned .rectangular holes inthe units so`thatthe Wide at sides of the bar areparallel to the; at front andrear facesof the stack of units, the Width of the bai' being on `the order ofone-third C. a single Vstraight metal bars extending through the of thelength of thelong sides of the rectangular units sogthat v A Y(1) thebar provides good'straightY support against sagging of the' stackv inithe middle ,when the bumperY is mounted by its ends with and rear facesvertical; and l its flat front D; mounting means Von the end; plates bywhich the vbumper'ma'y be secured to the front of la loading dock.

RefereneesV Citedv in the le Dfthis patentV Re. 24,276 1,239,880A

UNITED STATES YPATENTS FOREIGN PATENTS ,France Aug.

